I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
trouped trooped dropped torpedo trapped tripped drooped draped torpid tripod trepid dripped tripody trippet dropt trapt dropout
grouped trouped rouped siruped urped trooped dropped drooped syruped larruped propped groped cropped burped roupet roped chirruped
troupe trop troop trope strop stroppy